This was the first science image of Mars taken by THEMIS, February 19, 2002. It shows an area in Acheron Fossae, north of the giant volcano Olympus Mons, where mesas and valleys lie bounded by geologic faults. The image shows an area 11 by 6 miles (19 by 9 kilometers); the smallest details visible in the original image are 59 feet (18 meters) wide. Credit: NASA/JPL-Caltech/Cornell/Arizona State University

Ten years ago, on February 19, 2002, the Thermal Emission Imaging System (THEMIS), a multi-band camera on NASA’s Mars Odyssey orbiter, began scientific operations at the Red Planet. Since then, the camera has circled Mars nearly 45,000 times and taken more than half a million images at infrared and visible wavelengths.

“THEMIS has proven itself a workhorse,” said Philip Christensen from Arizona State University in Tempe. “It’s especially gratifying to me to see the range of discoveries that have been made using this instrument.”

Highlights of science results by THEMIS over the past 10 years include:

Confirming that hematite is widespread on Meridiani Planum, which led NASA to send one of its Mars Exploration Rovers there

Discovering carbon dioxide gas jets at the south polar ice cap in spring

Discovering that a large impact crater, Aram Chaos, once contained a lake

Discovering that Mars has more water-carved channels than previously thought

Discovering dacite on Mars, a more evolved form of volcanic lava not previously known on the Red Planet

THEMIS combines a 5-wavelength visual imaging system with a 9-wavelength infrared imaging system. By comparing daytime and nighttime infrared images of a given area, scientists can determine many of the physical properties of the rocks and soils on the ground.

Mars Odyssey has a two-hour orbit that is nearly “Sun-synchronous,” meaning that Odyssey passes over the same part of Mars at roughly the same local time each day. In September 2008, its orbit was shifted toward an earlier time of day, which enhanced THEMIS’ mineralogical detection capability.

“Both Odyssey and THEMIS are in excellent health, and we look forward to more years of science with them.” Said Christensen.

NASA launched the Mars Odyssey spacecraft April 7, 2001, and it arrived at Mars October 24, 2001. On arrival, the spacecraft spent several months in a technique called aerobraking, which involved dipping into the martian atmosphere to adjust its orbit. In February 2002, science operations began.